Abstract: A method and apparatus for practicing solid phase extraction of samples for analysis where the method comprises the steps of providing a cassette having a plurality of tubes, each containing an absorbent substrate and having an upper and a lower opening; applying a preconditioning liquid reagent to each tube of the cassette through the upper opening to render the substrate therein hydrophilic and drawing the liquid through the substrate until the liquid is at a predetermined height about the substrate; applying a liquid sample to be analyzed to each of the tubes of the cassette and drawing the sample through the substrate until the liquid is at a predetermined height in the tube with respect to the substrate; applying an eluate to each tube of the cassette to remove an eluent therefrom; and collecting the eluents from the cassette tubes. The apparatus automates this process and provides accurate and rapid separation of compounds in the sample.
Abstract: The presence of decay is determined in wood by testing a sample. The wood tested may be standing timber, cut timber or when coated in building structures. The testing occurs in very short time intervals so that tests can be carried out on timber in mills and the like. The method of testing includes heating a portion of a wood sample at a temperature in the range of about 220.degree. to 350.degree. C. to evaporate analytes from the wood, conveying the analytes in a sample gas flow into an ionizing chamber of an ion mobility spectrometer detector, ionizing the analytes within the ionizing chamber at a temperature in the range of about 220.degree. to 350.degree. C., generating an ion drift time signature in the detector, and comparing the signature with predetermined signatures representing decay in wood.
May 20, 1991
Date of Patent:
September 14, 1993
Forintek Canada Corporation
R. James Barbour, Ludmila L. Danylewych-May, Roger Sutcliffe
Abstract: A method and apparatus for detecting clot lysis, comprising allowing a blood sample containing a plasminogen activator to traverse a capillary track, wherein the capillary track contains a reagent capable of initiating blood clotting and the sample contacts the reagent as the sample flows through the track, the capillary track being of sufficient length and sufficiently small volume to allow blood to clot in the track before the sample reaches the end of the track and while a reserve sample volume remains available for continued capillary flow; allowing the sample to clot in the capillary track; and measuring time required for the sample to resume flowing as a measure of clot lysis.
Abstract: A method for separating HDL from whole blood anticoagulated with EDTA is disclosed. The method includes, as a first step, mixing the anticoagulated whole blood with an aqueous solution composed of magnesium .sup.++ cations and dextran sulfate 500 in such proportions and of such concentration(a) that substantially all of the LDL and VLDL lipoproteins and substantially all of the chylomicrons are precipitated while(b) substantially all of the HDL remains in solution.The method also includes the step of sedimenting the precipitated lipoproteins, the chylomicrons and the red blood cells by centrifuging, which can be low gravity centrifuging, and can include the step of determining the cholesterol, triglyceride, phospholipid or protein content of the supernatant.
Abstract: An indirect potentiometric method and diluent for the analysis of lithium are disclosed. The diluent includes effective amounts of a pH buffer, at least one lithium salt, and a non-cationic surfactant containing at least one hydrophobic group, at least one hydrophillic group and being substantially free of polyoxyethylene groups. Most preferably, the pH buffer is tris-(hydroxymethyl)aminomethane-phosphate, the lithium salt is lithium chloride, and the surfactant is 2,4,7,9-tetramethyl-5-decyn-4,7 diol.
October 19, 1990
Date of Patent:
May 5, 1992
Beckman Instruments, Inc.
Frank R. Shu, Chen-Yie Chien, Julie S. Kim
Abstract: Dispensing nozzles suffer from the problem of perfusion and can be relatively inaccurate in the amount of fluid dispensed each time. Described herein is a dispensing device which is provided with an improved nozzle construction. An exterior surface, having an aperture through which fluid is dispensed, has a second surface positioned adjacent to it. Further surfaces are arranged further up the nozzle. The arrangement of the surfaces is such that self-wiping of the device is maximized (if the device is also used for aspiration wherein the device is withdrawn from a supply of the liquid) and that perfusion is minimized during dispensing of the fluid contained therein. This is achieved by having the second surface angled to the first surface, defining an angle .alpha., relative to the first surface.